title: Effects of caffeinated vs. non-caffeinated alcoholic beverage on next-day hangover incidence and severity, perceived sleep quality, and alertness.
abstract: OBJECTIVE
  Beliefs about the effects of mixing caffeine and alcohol on hangover or sleep may play a role in motivation to consume these mixtures; therefore, information is needed about actual effects. We investigated whether intoxication with caffeinated vs. non-caffeinated beer differentially affected perceived sleep quality, sleepiness, and hangover incidence and severity the next morning.
  
  
  METHODS
  University students (89%) and recent graduate drinkers were randomized to receive: (1) beer with the equivalent of 69mg caffeine/12oz glass of regular beer (n=28) or (2) beer without caffeine (n=36), in sufficient quantity to attain a BrAC of 0.12g%. After an 8-h supervised sleep period, participants completed measures of hangover, sleep quality, sleep latency and time asleep, and sleepiness.
  
  
  RESULTS
  While caffeinated beer improved perceived sleep quality, effect sizes were greater for morning alertness than for quality while sleeping, with no effect on sleep latency or total sleep time. No effects were seen on hangover incidence or severity.
  
  
  CONCLUSIONS
  Mixing caffeine and alcohol does not significantly impair amount of sleep or sleep latency, hangover, or sleepiness the morning after drinking to intoxication in this population.
authors.affiliation: Providence Veterans Affairs Medical Center and Center for Alcohol and Addiction Studies, Brown University, Providence, RI, USA.
authors.forename: Damaris J
authors.initials: DJ
authors.lastname: Rohsenow
authors.forename: Jonathan
authors.initials: J
authors.lastname: Howland
authors.forename: Luisa
authors.initials: L
authors.lastname: Alvarez
authors.forename: Kerrie
authors.initials: K
authors.lastname: Nelson
authors.forename: Breanne
authors.initials: B
authors.lastname: Langlois
authors.forename: Joris C
authors.initials: JC
authors.lastname: Verster
authors.forename: Heather
authors.initials: H
authors.lastname: Sherrard
authors.forename: J Todd
authors.initials: JT
authors.lastname: Arnedt
mesh_terms: D000328:Adult; D019973:Alcohol-Related Disorders / Q000209:etiology / Q000517:prevention & control*; D000435:Alcoholic Intoxication / Q000150:complications; D001288:Attention; D001515:Beer; D002110:Caffeine / Q000627:therapeutic use*; D000697:Central Nervous System Stimulants / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D008297:Male; D010465:Perception; D012720:Severity of Illness Index; D012890:Sleep; D055815:Young Adult
chemical_list: D000697:Central Nervous System Stimulants; D002110:Caffeine
keywords: Alcohol; Caffeine; Energy drinks; Hangover; Sleep quality